CVE-2025-39682

Aliases:UBUNTU-CVE-2025-39682DEBIAN-CVE-2025-39682CGA-28j7-8244-4748CGA-3977-x56c-2vjjCGA-3fhq-c5x4-v7g3CGA-3hph-x63c-9574CGA-8375-c7rf-4mv4CGA-943r-4x6r-qv2cCGA-c5gr-p2mv-2p4rCGA-fc69-hvm4-37r5CGA-fx7m-mrvg-xgfqCGA-g26r-9hp4-mwxfCGA-jf9m-g9c8-cpjxCGA-jmvx-84r7-qhw8CGA-m786-r5m6-22q7CGA-mm67-frqp-w2p6CGA-q229-9q9f-vpgvCGA-qhw2-37r3-69m2CGA-qmrm-wjx3-rhmqCGA-r2fp-48cq-pmq4
Advisory lineage Upstream: 0 Downstream: 95
Undergoing Analysis
Published: 05 Sept 2025, 17:20
Last modified:19 Sept 2026, 03:56

Vulnerability Summary

Overall Risk (default)
high
70/100
CVSS Score
9.8 CRITICAL
v3.1 (cve.org)
EPSS Score
0.51% LOW
1% probability +0.48%
KEV
Listed
CISA
1 listing
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

05 Sept 2025, 17:20
Published
Vulnerability first disclosed
18 Sept 2026, 00:00
Added to CISA KEV
Linux Kernel Improper Check for Unusual or Exceptional Conditions Vulnerability
19 Sept 2026, 03:56
Last Modified
Vulnerability information updated
21 Sept 2026, 00:00
CISA Remediation Due
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Description

In the Linux kernel, the following vulnerability has been resolved: tls: fix handling of zero-length records on the rx_list Each recvmsg() call must process either - only contiguous DATA records (any number of them) - one non-DATA record If the next record has different type than what has already been processed we break out of the main processing loop. If the record has already been decrypted (which may be the case for TLS 1.3 where we don't know type until decryption) we queue the pending record to the rx_list. Next recvmsg() will pick it up from there. Queuing the skb to rx_list after zero-copy decrypt is not possible, since in that case we decrypted directly to the user space buffer, and we don't have an skb to queue (darg.skb points to the ciphertext skb for access to metadata like length). Only data records are allowed zero-copy, and we break the processing loop after each non-data record. So we should never zero-copy and then find out that the record type has changed. The corner case we missed is when the initial record comes from rx_list, and it's zero length.

CVSS Metrics

  • v3.1•HIGH•Score: 7.1CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
  • v3.1•CRITICAL•Score: 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.51%• Percentile: 42%

Techniques & Countermeasures

  • CWE-754•Improper Check for Unusual or Exceptional Conditions

    The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.

Affected Systems

  • chainguard•linux-aws-6.12

    < 6.12.76-r0 | all

  • chainguard•linux-aws-6.18

    < 6.18.17-r0

  • chainguard•linux-azure-6.12

    < 6.12.76-r0

  • chainguard•linux-azure-6.18

    all

  • chainguard•linux-desktop-6.18

    all | < 6.18.48-r0

  • chainguard•linux-firecracker-6.18

    < 6.18.44-r0

  • chainguard•linux-gcp-6.18

    < 6.18.17-r0

  • chainguard•linux-qemu-6.12

    < 6.12.76-r0

  • chainguard•linux-qemu-6.18

    < 6.18.17-r0

  • chainguard•linux-raspberry-pi

    < 20250916-r1

  • chainguard•linux-raspberry-pi-4

    < 20260911-r0

  • chainguard•linux-vmware-6.18

    < 6.18.17-r0

  • debian•linux

    < 6.1.153-1 | < 6.12.48-1 | < 6.16.5-1

  • debian•linux-6.1

    < 6.1.153-1~deb11u1

  • ubuntu•linux

    < 6.8.0-86.87

  • ubuntu•linux-allwinner-5.19

    all

  • ubuntu•linux-aws

    < 6.8.0-1041.43

  • ubuntu•linux-aws-5.0

    all

  • ubuntu•linux-aws-5.11

    all

  • ubuntu•linux-aws-5.13

    all

  • ubuntu•linux-aws-5.19

    all

  • ubuntu•linux-aws-5.3

    all

  • ubuntu•linux-aws-5.8

    all

  • ubuntu•linux-aws-6.14

    < 6.14.0-1015.15~24.04.1

  • ubuntu•linux-aws-6.2

    all

  • ubuntu•linux-aws-6.5

    all

  • ubuntu•linux-aws-6.8

    < 6.8.0-1041.43~22.04.1

  • ubuntu•linux-aws-fips

    < 6.8.0-1041.43+fips1

  • ubuntu•linux-azure

    all | < 6.8.0-1041.47

  • ubuntu•linux-azure-5.11

    all

  • ubuntu•linux-azure-5.13

    all

  • ubuntu•linux-azure-5.19

    all

  • ubuntu•linux-azure-5.3

    all

  • ubuntu•linux-azure-5.8

    all

  • ubuntu•linux-azure-6.11

    all

  • ubuntu•linux-azure-6.14

    < 6.14.0-1014.14~24.04.1

  • ubuntu•linux-azure-6.2

    all

  • ubuntu•linux-azure-6.5

    all

  • ubuntu•linux-azure-6.8

    < 6.8.0-1041.47~22.04.1

  • ubuntu•linux-azure-edge

    all

  • ubuntu•linux-azure-fde

    all | all

  • ubuntu•linux-azure-fde-5.19

    all

  • ubuntu•linux-azure-fde-6.2

    all

  • ubuntu•linux-azure-fips

    < 6.8.0-1044.50+fips1

  • ubuntu•linux-azure-nvidia

    < 6.8.0-1029.32

  • ubuntu•linux-azure-nvidia-6.14

    < 6.14.0-1007.7

  • ubuntu•linux-bluefield

    all | < 6.8.0-1012.16

  • ubuntu•linux-fips

    < 6.8.0-86.87+fips1

  • ubuntu•linux-gcp

    all | < 6.8.0-1042.45

  • ubuntu•linux-gcp-5.11

    all

Showing first 50 affected entries in server-rendered view.

References (28)